Control method of a gap adjuster of impact crusher and a gap adjuster

ABSTRACT

In an impact crusher, a rise of an advancing-retracting portion ( 65 ) of a gap adjuster ( 60 ) caused when a rebound plate ( 33 ) touches a rotor ( 32 ) or the rotation amount of the rotor ( 32 ) is detected to determine a zero-point position of the rebound plate ( 33 ) is determined based on the detected result, so that the zero-point position can be securely determined since it is not necessary to touch and vibrate the rebound plate with the rotor rotating at a high speed, and since the rebound plate ( 33 ) is not vibrated, the zero-point position can be securely determined without being influenced by the abrasion of the rebound plate ( 33 ) and the impact plate ( 322 ), thereby accurately adjusting gap (C).

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a control method of a gapadjuster of an impact crusher and a gap adjuster. More specifically, itrelates to a control method of a gap adjuster and a gap adjusterprovided on an impact crusher including a rotor having an impact body, arebound plate spaced apart from a rotation locus of the tip end of theimpact body, and a case for the rotor and the rebound plate to beattached.

[0003] 2. Description of Related Art

[0004] Conventionally, it is known to crush an object such as great massof concrete and asphalt taken out from demolition site of a building anda quarry and natural stone such as andesite with an impact crusher.

[0005] Such impact crusher crushes the object by hitting the object withan impact plate (impact body) of a revolving rotor and by colliding theobject hit by the impact body with a rebound plate. At this time, sincethe size of the object (the size of the object after being crushed) isdetermined by the gap between the rotation locus of the impact plate andthe rebound plate, the gap has to be accurately adjusted and maintainedby moving the rebound plate in order to obtain the object of apredetermined size.

[0006] For adjusting the gap, in a method disclosed in Japanese PatentLaid-Open Publication No. Hei8-266921, a rebound plate is brought intocontact with an impact plate, the contact position being set as azero-point position of the rebound plate, and the rebound plate is movedback by a predetermined distance with a hydraulic cylinder, therebyautomatically adjusting the gap relative to the impact plate.

[0007] However, though the rebound plate can be seamlessly andcontinuously moved when the rebound plate is moved by the hydrauliccylinder as in the above method, it is difficult to minutely move therebound plate or securely stop at a desired position while moving, sothat accurate movement by a desired movement distance cannot beconducted. Accordingly, the gap between the rebound plate and the impactplate cannot be accurately adjusted, and gap accuracy is deteriorated.

[0008] Further, according to the above method, when the rebound plate isadjusted to zero-point position, the rebound plate is brought closer tothe rotor while rotating the rotor at a high speed before bringing therebound plate into contact with the impact plate, where the magnitude ofvibration of the rebound plate periodically generated by the contact isdetected. When the magnitude of the vibration reaches a predeterminedvibration limit, the position of the rebound plate is determined as thezero-point position.

[0009] However, since the rebound plate is vibrated by the rotation ofthe rotor while determining the zero-point position, it is vague whichposition during vibration should be determined as the zero-pointposition, so that it is difficult to instantly determine accuratezero-point position.

[0010] Further, since the magnitude of the vibration of the reboundplate greatly differs according to abrasion of the rebound plate and theimpact plate, the zero-point position is shifted on account of theabrasion of the rebound plate and the impact plate when the magnitude ofthe vibration is always compared with the same vibration limit, so thatthe zero-point position cannot be accurately determined. Considering thefact that abrasion changes on account of various factors, it isvirtually impossible to set the vibration limit in accordance withabrasion.

[0011] Accordingly, since the gap is adjusted while determination of thezero-point position is inaccurately conducted, the gap cannot beaccurately adjusted.

SUMMARY OF THE INVENTION

[0012] An object of the present invention is to provide a control methodof a gap adjuster of an impact crusher and a gap adjuster capable ofaccurately adjusting the gap between the rotation locus of the tip endof the impact body and the rebound plate.

[0013] A control method of a gap adjuster of an impact crusher accordingto an aspect of the present invention includes the steps of: inputting adesired gap amount between a rotation locus of a tip end of an impactportion of a rotor and a rebound plate; moving the rebound plate towardthe rotor using a mechanical moving mechanism; determining a zero-pointposition of the rebound plate based on interference between the reboundplate and the rotation locus of the tip end of the impact portion;moving the rebound plate to be away from the zero-point position usingthe mechanical moving mechanism; and stopping the movement of therebound plate in a direction away from the zero-point position when anactual gap amount of the rebound plate reaches the desired gap amount.

[0014] Incidentally, in the following explanation, the “rotation locusof the tip end of the impact portion” is sometimes simplified as “impactportion”.

[0015] According to the control method of the gap adjuster, in order toadjust the gap between the rebound plate and the impact portion, it isonly necessary to input the desired gap amount in adjusting the gapbetween the rebound plate and the impact portion, and the rebound plateat the zero-point position automatically moves until the desired gapamount is reached. At this time, since the rebound plate is moved, notby a conventional hydraulic cylinder, but by a mechanical movingmechanism such as screw-type and rack-and-pinion type, the movementamount can be minutely controlled based on screw pitch and circle pitchand the rebound plate can be stopped at any desired position.Accordingly, the rebound plate securely moves from the zero-pointposition by the desired gap amount, thereby accurately conducting thegap adjustment.

[0016] Since the gap can be accurately adjusted, final object (crushedobject) of a desired grain size can be securely obtained.

[0017] A control method of a gap adjuster of an impact crusher accordingto another aspect of the present invention includes the steps of: movinga rebound plate toward a rotor; detecting initial contact of the reboundplate with the rotor based on a rise of a rebound plate supportsupporting the rebound plate; after detecting the rise of the reboundplate support, moving the rebound plate to be away from the rotor;rotating the rotor to detect whether the rotor again touches the reboundplate or not based on the rise of the rebound plate support; repeatingthe movement of the rebound plate to be away from the rotor and therotation of the rotor until the rise of the rebound plate support is notdetected; and determining the position of the rebound plate when it isjudged that the rise of the rebound plate support is not detected as azero-point position.

[0018] According to the above control method of the gap adjuster, therebound plate is brought into contact with the rotor and the rise of therebound plate support caused by the contact is detected, based on whichthe zero-point position of the rebound plate is detected. Accordingly,it is not necessary to bring the rotor into contact with the reboundplate while rotating at high-speed, so that the zero-point position canbe securely determined. Further, since the rebound plate is notvibrated, the zero-point position can be determined without beinginfluenced by the abrasion of the rebound plate and the impact portion.Accordingly, by securely adjusting the zero-point position and movingthe rebound plate from the zero-point position, the gap between therebound plate and the impact portion can be accurately adjusted.

[0019] A control method of a gap adjuster of an impact crusher accordingto still another aspect of the present invention includes the steps of:rotating the rotor; detecting initial contact of the rebound plate withthe rotor when the rotation amount of the rotor becomes less than apredetermined rotation amount; after detecting that the rotation amountof the rotor does not exceed the predetermined rotation amount, movingthe rebound plate to be away from the rotor; rotating the rotor todetect whether the rotor again touches the rebound plate or not byjudging that the rotation amount of the rotor does not exceed thepredetermined rotation amount; repeating the movement of the reboundplate to be away from the rotor and the rotation of the rotor until therotation of the rotor exceeds the predetermined rotation amount; anddetermining the position of the rebound plate when the rotation of therotor exceeds the predetermined rotation amount as a zero-pointposition.

[0020] According to thus arranged control method of the gap adjuster,the rotor is brought into contact with the rebound plate and therotation amount of the rotor restricted by the contact is detected,based on which the zero-point position of the rebound plate isdetermined. Accordingly, it is not necessary to determine the zero-pointposition based on the vibration of the rebound plate, so that the gapbetween the rebound plate and the impact portion can be rapidly andaccurately adjusted.

[0021] A control method of a gap adjuster of an impact crusher accordingto further aspect of the present invention includes the steps of: movinga rebound plate toward the rotor; detecting initial contact of therebound plate with the rotor based on a rise of a rebound plate supportsupporting the rebound plate; after detecting the rise of the reboundplate support, moving the rebound plate to be away from the rotor;rotating the rotor to detect whether the rotor again touches the reboundplate or not by judging that the rotation amount of the rotor does notexceed a predetermined rotation amount; repeating the movement of therebound plate to be away from the rotor and the rotation of the rotoruntil the rotation of the rotor exceeds the predetermined rotationamount; and determining the position of the rebound plate when therotation of the rotor exceeds the predetermined rotation amount as azero-point position.

[0022] According to the above control method, the zero-point position ofthe rebound plate can be securely set by combining the above-describedrise-detection and rotation-detection, and following effect can beobtained.

[0023] In the above-described rise-detection method, whether the reboundplate has reached to the zero-point position or not is detected based onthe rise of the rebound plate support caused by the contact of the rotorwith the rebound plate. However, when the rotor enters into the reboundplate, the rebound plate support may not be raised in spite of themutual contact. In this case, it is unclear whether the rebound platesupport is not raised because the rotor enteres thereto or because therotor is not in contact with the rebound plate, thereby causing troublein determining the zero-point position.

[0024] On the other hand, in the above-described rotation-amountdetection method, the initial contact of the rebound plate with therotor when the rotor is rotated toward the rebound plate is detected bythe rotation amount of the rotor of less than a predetermined rotationamount. However, it is likely that the rotation amount of the rotorexceeds the predetermined rotation amount before the rotor is in contactwith the rebound plate according to the position of the rebound plate instarting rotation of the rotor, thereby causing detection error.

[0025] By combining the rise-detection and the rotation-amount detectionas in the above aspect of the present invention, the initial contactbetween the rebound plate and the rotor is detected based on the rise ofthe rebound plate support, so that the detection error likely to becaused in the rotation-amount detection can be securely prevented.Further, since whether the rebound plate has reached the zero-pointposition or not is detected based on the rotation amount of the rotor,even when the rotor enters into the rebound plate, the entering can besecurely recognized based on the rotation amount of the rotor, so thatthe trouble for determining the zero-point position can be avoided.Accordingly, the zero-point position can be further accuratelydetermined.

[0026] A control method of a gap adjuster of an impact crusher accordingto still further aspect of the present invention includes the steps of:recognizing a current gap between a rotation locus of a tip end of animpact portion of a rotor and a rebound plate in advance; inputting adesired movement amount of the rebound plate relative to the rotationlocus of the tip end of the impact portion; moving the rebound platetoward or away from the rotor, and stopping the rebound plate when anactual movement amount of the rebound plate reaches the desired movementamount.

[0027] According to the above control method of gap adjuster, thecurrent gap amount is recognized in advance and the rebound plate ismoved by the desired movement amount relative to the current position toadjust the gap. Accordingly, there is no need for colliding the reboundplate with the impact portion to vibrate, thereby accurately conductingthe gap adjustment.

[0028] In the above, the rebound plate may preferably be moved using amechanical moving mechanism.

[0029] Accordingly, since the rebound plate is moved not by a hydrauliccylinder as in a conventional arrangement but by a mechanical movingmechanism, the rebound plate can be accurately moved by the desiredmovement amount, thereby further improving the gap adjustment accuracy.

[0030] A gap adjuster of an impact crusher according to still furtheraspect of the present invention, the impact crusher having: a rotorhaving an impact portion; a rebound plate spaced apart from a rotationlocus of a tip end of the impact portion by a gap; and a case for therotor and the rebound plate to be attached, has: a rebound-plate-sidecomponent attached to the rebound plate; a case-side component screwedto or meshed with the rebound-plate-side component to be attached to thecase; a rebound plate drive for rotating the case-side component to movethe rebound plate; a movement sensor for detecting the movement amountof the rebound plate; a set value inputting device for setting andinputting a desired movement amount or a desired gap amount of therebound plate; and a controller for controlling the rebound plate drivebased on a detection signal from the movement sensor and the desiredmovement amount or the gap amount inputted by the set value inputtingdevice.

[0031] According to the above gap adjuster, the above-describedmechanically-driven control method of the present invention isimplemented to attain an object of the present invention.

[0032] Specifically, following steps of: inputting a desired gap amountbetween the rotation locus of the tip end of the impact portion of therotor and the rebound plate; rotating the case-side component to movethe rebound plate toward the rotor; determining a zero-point position ofthe rebound plate based on interference between the rebound plate andthe rotation locus of the tip end of the impact portion; rotating thecase-side component to move the rebound plate to be away from thezero-point position using the mechanical moving mechanism; detecting anactual movement amount of the rebound plate in the direction to be movedaway from the rotor; and comparing the actual movement amount of therebound plate and the gap amount, are conducted.

[0033] Further, according to the gap adjuster, desired movement amountis inputted instead of inputting the desired gap amount, and the reboundplate is moved not from the zero-point position but from the currentrebound plate position to achieve the above-described control method inaccordance with the movement amount.

[0034] A gap adjuster of an impact crusher according to still furtheraspect of the present invention, the impact crusher having: a rotorhaving an impact portion; a rotor drive for rotating the rotor; and arebound plate spaced apart from a rotation locus of a tip end of theimpact portion by a gap, the gap adjuster has: a rebound plate supportfor movably supporting the rebound plate; a rebound plate drive fordriving the rebound plate support to move the rebound plate; a movementsensor for detecting the movement amount of the rebound plate; a risesensor for detecting the rise of the rebound plate support when therebound plate touches the rotor; a set value inputting device forsetting and inputting a desired gap amount between the rebound plate andthe impact portion; and a controller for controlling the rebound platedrive and the rotor drive based on a detection signal from the movementsensor and the desired gap amount inputted by the set value inputtingdevice.

[0035] According to the above gap adjuster, the above-describedrise-detection control method of the present invention is implemented byconducting the following steps.

[0036] Specifically, following steps of: inputting a desired gap amountbetween the rebound plate and the rotation locus of the tip end of theimpact portion; driving the rebound plate support to move the reboundplate toward the rotor; detecting initial contact of the rebound platewith the rotor based on the rise of the rebound plate support supportingthe rebound plate; after detecting the rise of the rebound platesupport, moving the rebound plate to be away from the rotor by apredetermined amount; rotating the rotor to detect whether the rotoragain touches the rebound plate or not based on the rise of the reboundplate support; repeating the movement of the rebound plate to be awayfrom the rotor by the predetermined amount and the rotation of the rotoruntil the rise of the rebound plate support is not detected; anddetermining the position of the rebound plate when it is judged that therise of the rebound plate support is not detected as a zero-pointposition, are conducted.

[0037] A gap adjuster of an impact crusher according to still furtheraspect of the present invention, the impact crusher having: a rotorhaving an impact portion; a rotor drive for rotating the rotor; and arebound plate spaced apart from a rotation locus of a tip end of theimpact portion by a gap, the gap adjuster has: a rebound plate supportfor movably supporting the rebound plate; a rebound plate drive fordriving the rebound plate support to move the rebound plate; a movementsensor for detecting the movement amount of the rebound plate; arotation sensor for detecting the rotation amount of the rotor, a setvalue inputting device for setting and inputting a desired gap amountbetween the rebound plate and the impact portion; and a controller forcontrolling the rebound plate drive and the rotor drive based on adetection signal from the movement sensor and the desired gap amountinputted by the set value inputting device.

[0038] According to the above gap adjuster, following steps areconducted to achieve the rotation-detection control method, therebyachieving an object of the present invention.

[0039] Specifically, the following steps of: inputting a desired gapamount between the rebound plate and the rotation locus of the tip endof the impact portion; rotating the rotor; detecting initial contact ofthe rebound plate with the rotor when the rotation amount of the rotorbecomes less than a predetermined rotation amount; after detecting thatthe rotation amount of the rotor does not exceed the predeterminedrotation amount, moving the rebound plate to be away from the rotor by apredetermined amount; rotating the rotor to detect whether the rotoragain touches the rebound plate or not by judging that the rotationamount of the rotor does not exceed the predetermined rotation amount;repeating the movement of the rebound plate to be away from the rotor bythe predetermined amount and the rotation of the rotor until therotation of the rotor exceeds the predetermined rotation amount; anddetermining the position of the rebound plate when the rotation of therotor exceeds the predetermined rotation amount as a zero-pointposition, are conducted.

[0040] A gap adjuster of an impact crusher according to still furtheraspect of the present invention, the impact crusher having: a rotorhaving an impact portion; a rotor drive for rotating the rotor; and arebound plate spaced apart from a rotation locus of a tip end of theimpact portion by a gap, the gap adjuster has: a rebound plate supportfor movably supporting the rebound plate; a rebound plate drive fordriving the rebound plate support to move the rebound plate; a movementsensor for detecting the movement amount of the rebound plate; a risesensor for detecting the rise of the rebound plate support when therebound plate touches the rotor; a rotation sensor for detecting therotation amount of the rotor; a set value inputting device for settingand inputting a desired gap amount between the rebound plate and theimpact portion; and a controller for controlling the rebound plate driveand the rotor drive based on a detection signal from the rise sensor, adetection signal from the rotation sensor, and the desired gap amountinputted by the set value inputting device.

[0041] According to the above gap adjuster, following steps areconducted to achieve the control method combining the rise-detection andthe rotation-detection, thereby achieving an object of the presentinvention.

[0042] Specifically, following steps of: inputting a desired gap amountbetween the rebound plate and the rotation locus of the tip end of theimpact portion; moving a rebound plate toward the rotor by driving therebound plate support; detecting initial contact of the rebound platewith the rotor based on the rise of the rebound plate support supportingthe rebound plate; after detecting the rise of the rebound platesupport, moving the rebound plate to be away from the rotor by apredetermined amount; rotating the rotor to detect whether the rotoragain touches the rebound plate or not by judging that the rotationamount of the rotor does not exceed a predetermined rotation amount;repeating the movement of the rebound plate to be away from the rotor bythe predetermined amount and the rotation of the rotor until therotation of the rotor exceeds the predetermined rotation amount; anddetermining the position of the rebound plate when the rotation of therotor exceeds the predetermined rotation amount as a zero-pointposition, are conducted.

BRIEF DESCRIPTION OF THE DRAWINGS

[0043]FIG. 1 is a side elevational view showing a mobile crushingmachine installed with an impact crusher according to first embodimentof the present invention;

[0044]FIG. 2 is an illustration of the mobile crushing machine seen froma side from which the object is to be charged;

[0045]FIG. 3 is a plan view showing the mobile crushing machine;

[0046]FIG. 4 is a side elevational view showing the impact crusher;

[0047]FIG. 5 is a vertical cross section showing a part of the internalstructure of the impact crusher;

[0048]FIG. 6A is a vertical cross section showing a gap adjuster of theimpact crusher;

[0049]FIG. 6B is a cross section taken along VI-VI line of FIG. 6A;

[0050]FIG. 7 is a block diagram of the impact crusher;

[0051] FIGS. 8 are illustrations for explaining full-auto mode duringgap adjustment, in which FIG. 8A shows a condition before adjustment,FIG. 8B shows lowering operation, FIG. 8C shows repetition of routine,FIG. 8D shows zero-point position and FIG. 8E shows gap adjustment,respectively;

[0052]FIG. 9 is a flow chart showing the full-auto mode;

[0053]FIG. 10 is a continuation of the flow chart of the full-auto mode;

[0054]FIG. 11 is a flow chart showing an automatic mode; and

[0055]FIG. 12 is a cross section showing a primary portion of the gapadjuster according to second embodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT(S)

[0056] Preferred embodiments of the present invention will be describedbelow with reference to attached drawings.

First Embodiment

[0057]FIG. 1 is a side elevational view showing an entire mobilecrushing machine 1 according to first embodiment, FIG. 2 is anillustration showing the mobile crushing machine 1 seen from a side fromwhich an object is to be charged, and FIG. 3 is a plan view of themobile crushing machine 1.

[0058] [Outline of Mobile Crushing Machine]

[0059] As shown in FIGS. 1 to 3, the mobile crushing machine 1 has abase 2 onto which a work machine 3 and a power section 4 are mounted.

[0060] The base 2 has a pair of crawler type running sections 10 fordriving in work site, and a frame 20 with the running section 10 beingattached and the work machine 3 and the power section 4 being mounted.

[0061] The work machine 3 has an impact crusher (referred to as acrusher hereinafter) 30 installed approximately at the center of thebase 2, an object feeding portion 40 for feeding an object to thecrusher 30 and a discharge belt conveyer 50 for discharging the crushedobject.

[0062] The power section 4 is a power source of the running section 10,the crusher 30, the discharge belt conveyer 50 etc., which includes anengine (not shown), a hydraulic pump 6 (FIG. 7) driven by the engine, amain valve 8 (FIG. 7) for controlling hydraulic oil from the hydraulicpump 6 etc. A drive lever 4A for driving and rotating the mobilecrushing machine 1 and an upper control box (not shown) with indicatorsfor driving being disposed thereon are provided on the upper side of thepower section 4, and a side control box (not shown) for operating thework machine 3 is provided adjacent to the side of the power section 4.

[0063] The crusher 30 side of the power section 4 is a first workingfloor 28 formed by an upper surface of the power section 4, wherevarious works such as operation of the drive lever 4A, maintenance andinspection of the crusher 30 are conducted.

[0064] In the following explanation, the discharge belt conveyer 50 sideof the mobile crushing machine 1 is referred to as “front side” (rightside in FIG. 1), the object feeding portion 40 side is referred to as“rear side” (left side in FIG. 1) and the side orthogonal with the“front” and “rear” sides (right and left direction in FIG. 2) isreferred to as “lateral” sides for the sake of convenience.

[0065] The running section 10 is provided on a crawler frame 22 forminga part of the frame 20 and has a hydraulic motor 11 on the front side ofthe crawler frame 22. An endless track crawler belt 13 driven by thehydraulic motor 11 is wound around a sprocket 11A of the hydraulic motor11 and an idler 12 on the other side. The hydraulic motor 11 is drivenby the hydraulic pump of the power section 4 through a control valve(not shown).

[0066] The frame 20 has a main frame 21 on which the crawler frame 22 isattached as well as the pair of the crawler frames 22. A flat crushermount 211 is provided on a part of the main frame 21, where the crusher30 is mounted. A hopper frame 23 for the object feeder 40 to be mountedand an engine frame 24 for the power section 40 to be mounted are fixedon the main frame 21.

[0067] As shown in FIGS. 4 and 5, the crusher 30 has a case 31 having acharging hole 31A of the object to be crushed, in which a rotor 32having a rotor body 321 and an impact plate 322 and rebound plates 33spaced apart from a rotation locus A of the tip end of the impact plate322 by gaps C1, C2 and C3 are disposed.

[0068] In the crusher 30, the object charged from the charging hole 31Ais hit by the rotating impact plate 322 and collided with the reboundplate 33 after being hit and scattered to be crushed, which falls on thedischarge belt conveyer 50 from a discharge hole 31B on the bottom sideof the case 31 to be discharged.

[0069] The object feeding portion 40 has a hopper 41 for the object tobe loaded, and a grizzly feeder 42 disposed beneath the hopper 41 with aslight gap retained.

[0070] The hopper 41 is supported on the hopper frame 23 of the frame 20by supports 411 provided on four corners thereof and greatly widenedupward.

[0071] The feeder 42 is a vibration-type having a vibrator 421 driven bythe hydraulic power from the power section 4, which is supported on thehopper frame 23 through a plurality of helical springs 422 and isvibrated within the gap while avoiding contact with the hopper 41 tofeed the object toward the crusher 30. The end of the hopper 41 and thefeeder 42 are, as shown in double-dotted line in FIG. 4A, inserted inthe charging hole 31A of the crusher 30, so that the object is securelycharged into the crusher 30.

[0072] The feeder 42 not only feeds the object to the crusher 30 butalso selects small objects unnecessary to be crushed by a comb-shapedgrizzly 423 (FIG. 3) to throw them downward. The sifted objects falls onanother belt conveyer 43 shown in FIGS. 1 to 3 to be discharged or fallson the discharge belt conveyer 50 by switching a damper (not shown) tobe discharged together with the crushed objects.

[0073] The discharge belt conveyer 50 has a base end in feedingdirection (left side in FIG. 1) located beneath the frame 20 totransport the crushed object discharged from the discharge hole 31B ofthe crusher 30 or the discharged objects from the grizzly 423 (the sameas the charged object) toward a distal side (right side in FIG. 1). Thedischarge belt conveyer 50 is of triple-bending structure, wheredischarge height on the distal side is sufficiently secured so that workcan be securely conducted without employing second belt conveyer. Thedischarge belt conveyer 50 is also driven by the hydraulic power fromthe power section 4.

[0074] A magnetic separator 51 is disposed in around the middle of thedischarge belt conveyer 50 supported by the frame 20, where metallicmaterial such as rebar obtained in crushing concrete mass ismagnetically absorbed by a permanent magnet to be discharged by anannexed belt conveyer.

[0075] [Crusher]

[0076] The crusher 30 will be described below in detail with referenceto FIGS. 4 and 5.

[0077] The case 31 of the crusher 30 is a separate type having a fixedcase 70 fixed to the frame 20 (FIG. 1) and a movable case 80 attached tothe upper side of the fixed case 70. The rotor 32 is disposed in thefixed case 70 and, as shown in FIG. 5, the rebound plate 33 is attachedto the movable case 80.

[0078] The fixed case 70 is a box with the entire upper side area beingopened and having the discharge hole 31B being located on the bottomside thereof, both of the sides of the fixed case 70 in lateraldirection being fixed-case side portion 72. Respective fixed-case sideportions 72 have two access doors 720 and 721 (only one of thefixed-case portion being illustrated), the access doors 720 and 721being opened to check the inside of the case 31 and whether the objectis stuffed in the discharge hole 31B on the bottom side of the case 31.The size and number of the access door may be determined as desired.

[0079] On the other hand, the movable case 80 is a lid-shaped bodycovering the upper opening of the fixed case 70, the peripheral end onthe rear side of the movable case 80 forming a part of the charging hole31A. Both sides of the movable case 80 in lateral direction aremovable-case side portion 82. The respective movable-case side portions82 are located outside relative to the fixed-case side portion 72 of thefixed case 70, and lower periphery 821 of the fixed-case side portion 82swallows upper periphery 724 as the upper side of the fixed-case sideportion 72. In other words, in the case 31 of the present embodiment,the upper periphery 724 and the lower periphery 821 overlap in lateraldirection and the parting line S-S of the fixed case 70 and the movablecase 80 are formed along the overlapped portion.

[0080] The fixed case 70 and the movable case 80 are connected by a turnmechanism 39 provided on an upper portion opposite to the charging hole31A, so that the movable case 80 turns upward to be opened relative tothe fixed case 70 and sinks deeply downward until the lower periphery821 touches a contact portion 725 around the turning axis of the turnmechanism 39. In other words, the condition shown in solid line in FIG.4 is working position of the movable case 80 at which crushing work isconducted. The condition shown in double-dotted line where the movablecase 80 is opened is movable case maintenance position Fm, at which therebound plate 33 (331, 332, 333) is exposed to be reversed and exchangedby opening the movable case 80. The condition where the movable case 80is deeply sunk is a transport position Fs of the movable case 80, atwhich the total height of the case 31 is reduced to match the mobilecrushing machine 1 with height restriction in transportation by atrailer.

[0081] The fixed case 70 and the movable case 80 are connected by thehydraulic cylinder 394 slightly closer to the charging hole 31A relativeto the turn mechanism 39. The hydraulic cylinder 394 is actuated inturning the movable case 80 to assist turning movement of the movablecase 80 of great weight. The hydraulic cylinder 394 is disposed so thatcylinder thereof is located on the upper side and rod thereof is locatedon the lower side to prevent dust etc. from depositing on the rod-sideend of the cylinder and improve durability of packing etc.

[0082] The rotor 32 of the crusher 30 is supported by a bearing (notshown) on the outside of the case 31 and has a pulley 34 on an endthereof. A hydraulic motor (rotor drive) 35 shown in double-dotted lineis disposed on the outside of the case 31 and a V-belt 37 is woundaround a pulley 36 of the hydraulic motor 35 and the pulley 34. In otherwords, the rotor 32 is rotated by the hydraulic motor 35 through theV-belt 37. The hydraulic motor 35 is driven by hydraulic power from thehydraulic pump of the power section 4 through the control valve 8A inthe main valve 8.

[0083] The impact plate 322 of the rotor 32 is continuously providedalong the lateral direction (axis line direction of the rotor body 321)in a range slightly narrower than the width of the case 31, the impactplate 322 projecting in plural (four in the present embodiment) at equalinterval along the circumference of the rotor body 321. The impact plate322 is capable of attachment and detachment and is reversed or exchangedwith a new impact plate in accordance with abrasion thereof.

[0084] Next, in FIG. 5, the rebound plate 33 of the crusher 30 includesa first rebound plate 331, a second rebound plate 332 and a thirdrebound plate 333 arranged sequentially along the rotation direction ofthe rotor 32 from the charging hole 31A (FIG. 4) side.

[0085] The first rebound plate 331 is greater than the other plates, soas to securely receive bigger object just charged in. A pair of engagingprojections 331A are provided on the backside of the first rebound plate331, the engaging projections 331A being engaged between engagementportions 334A on the lower side of a first arm 334 and being held by ascrew fixing component 334B provided on one of the engagement portion334A and a stop 334C provided on an end in lateral direction. The firstrebound plate 331 are closely arranged in plural in lateral direction,which can respectively be inserted and pulled out in lateral directionby releasing the fixing component 334B and the stop 334C, so that therebound plates 331 are reversed or exchanged with new rebound plate inaccordance with abrasion thereof.

[0086] The second and the third rebound plates 332 and 333 have the sameshape, which are held between engagement portions 335A provided on thelower portion of a second arm 335 by a fixing component 335B and a stop335C through engaging projections 332A and 333A on the backside. Thesecond and the third rebound plates 332 and 333 can also be insertedinto and pulled out from the second arm 335 to be exchanged inaccordance with abrasion thereof. Since the abrasion during crushingprocess equally occurs on the entire side of the second and the thirdrebound plates 332 and 333 of moderate size, the second rebound plate332 and 333 are not used in reversed manner. However, the second and thethird rebound plates 332 and 333 may be arranged in reversible manner asin the first rebound plate 331.

[0087] The first arms 334 and the second arms 335 are arranged in pairand in parallel spaced apart in lateral direction, the respective armsbeing integrally connected with connection plates 334D and 335D andconnection bars 334E and 335E. The respective second arms 335 arelocated inside the pair of the first arm 334. Both of the upper side ofthe first and the second arms 334 and 335 are supported in upwarddirection in the case 31. On the other hand, the lower side of the firstand the second arms 334 and 335 are suspended by an expandable first andsecond gap adjuster 60 (61, 62) attached to the connection bars 334E and335E.

[0088] The first and the second gap adjuster 61 and 62 are expanded andcontracted by driving the hydraulic motor (rebound plate drive) 64 ofthe drive mechanism 63 on the upper end, where, as described below indetail, a screw-type mechanical moving mechanism 69 (see FIGS. 6A and6B) having nut-shaped component and bolt-shaped component. The expansionand contraction of the first and the second gap adjusters 61 and 62turns the first and the second arms 334 and 335 around the turning shaft38, thereby adjusting the dimension of respective gaps C1, C2 and C3between the rotation locus A on the tip end of the impact plate 322 andthe first to third rebound plates 331 to 333.

[0089] Incidentally, the second gap adjuster 62 adjusts the gap C3 atthe third rebound plate 333 between the second and the third reboundplates 332 and 333. This is because the adjustment of the gap C3 isimportant for determining final grain size of the object. The gap C2 atthe second rebound plate 332 provided on the common second arm 335 isautomatically adjusted by adjusting the gap C3 in accordance withrelationship of mutual position of the second and the third reboundplates 332 and 333.

[0090] A bending restriction link 336 for restricting rotation inexpanding direction of the first gap adjuster 61 is provided on thefirst arm 334. The restriction link 336 prevents excessive stretch ofthe first gap adjuster 61 to restrict turning amount of the first arm334. On the other hand, the turning amount of the second arm 335 isrestricted by contact with the first arm 334.

[0091] On the first arm 334, a liner 337 capable of inserting andpulling out is attached above the first rebound plate 331 in order toprotect the first arm 334 from the crushed object etc.

[0092] In the crusher 30, a second working floor 29 is provided on anupper side of a pulley cover 75 of one of the fixed-case side portions72 of the fixed case 70 at the same height as the first working floor28. The second working floor 29 is constructed by a scaffolding boardcomponent extending in front and rear direction of the fixed-case sideportion 72 and is fixed to the fixed-case side portion 72 with a boltetc. A front end of the second working floor 29 is adjacent to the firstworking floor 28, the respective working floors 28 and 29 being formedalong angled two edges of substantially flat tetragon crusher 30, sothat worker can easily move between the respective working floors 28 and29.

[0093] When the movable case 80 is at the maintenance position, thecrusher 30 can be easily accessed from the second working floor 29striding over the fixed case 70. Further, the hopper 41 can be accessedby striding over the hopper 41 and the front of the feeder 42 (on theside of the charging hole 31A) to move easily onto the feeder 42.

[0094] [Detailed Description of Gap Adjuster]

[0095] The gap adjuster 60 will be described in detail with reference toFIG. 6A

[0096] Incidentally, both of the first and the second gap adjusters 61and 62 have the same construction, and will be collectively describedbelow as the gap adjuster 60.

[0097] In FIGS. 5 and 6A, the gap adjuster 60 has the drive mechanism 63and a rod-shaped advancing-retracting portion 65 driven by the drivemechanism 63.

[0098] The drive mechanism 63 is attached on a mount base 805 fixed onthe upper side of the movable case 80 by bolt through a pair ofvertically superposed coned disc springs 806 and has a spring-receivingplate 631 on the coned disc spring 806. A through-hole 631A coaxial withthrough-holes 81A and 805A drilled on the movable case 80 and the mountbase 805 is provided on the spring-receiving plate 631. Theadvancing-retracting portion (rebound plate support) 65 is inserted intothe through-holes 81A, 805A and 631A.

[0099] The drive mechanism 63 has an exterior case 632 provided on thespring-receiving plate 631. An accommodating portion 632A foraccommodating the upper end of the advancing-retracting portion 65 isprovided on the exterior case 632. A cylindrical gear 633 having ahollow portion 633A of hexagonal horizontal cross section as shown indouble-dotted line in FIG. 6B is rotatably disposed in the accommodatingportion 632A As shown in the horizontal cross section, a flat hexagonalfitting portion 661 provided on the advancing-retracting portion 65 isfitted into the hollow portion 633A of the cylindrical gear 633, so thatthe advancing-retracting portion 65 is rotated together with therotation of the cylindrical gear 633.

[0100] The cylindrical gear 633 meshes with a gear 634 of smallerdiameter and the gear 634 is connected to the rotation shaft of thehydraulic motor 64. Accordingly, the advancing-retracting portion 65 isrotated by the hydraulic motor 64. At this time, the rotation of thehydraulic motor 64 is decelerated between the gear 634 and thecylindrical gear 633 to be transmitted to the advancing-retractingportion 65. The meshed portion between the cylindrical gear 633 and thegear 634 are lubricated by lubricant oil injected into the exterior case632. Further, as shown in FIG. 7, the hydraulic motor 64 is driven byhydraulic power from the hydraulic pump 6 supplied through respectivecontrol valves 8B and 8C in the main valve 8.

[0101] The exterior case 62 is attached to the mount base 805, i.e. themovable case 80, through a lower end flange of a cylinder 635 providedon the lower side thereof. The flange of the cylinder 635 is sandwichedby a pair of upper and lower rubber materials 636 and 637, and theflange is attached by a sleeve 638 and a bolt 639 penetrating the flangeand the rubber materials 636 and 637.

[0102] Incidentally, though only one of the attachment portions havingthe rubber materials 636 and 637 is shown in FIG. 6A, the attachmentportion is actually provided on an opposing position around rotationcenter of the cylindrical gear 633 (advancing-retracting portion 65), sothat the drive mechanism 63 is attached to the movable case 80 at twopositions.

[0103] Vertical section of the cylinder 635 in FIG. 6A is sized to coverthe circumference of the coned disc spring 806 and the spring-receivingplate 631 to prevent dust etc from falling on the components.

[0104] On the other hand, the advancing-retracting portion 65 has a nut66 (case-side component) attached on the movable case 80 side, and abolt 67 (rebound-plate-side component) with lower end thereof beingattached to the connection bars 334E and 335E of the rebound plate 33, ascrew 67A carved on the bolt 67 being screwed to a screw 66A carved onthe inside of the nut 66.

[0105] The fitting portion 661 is provided on the upper side of the nut66 and, as shown in FIG. 6B, a manipulating portion 662 of flathexagonal shape slightly smaller than the fitting portion 661 isattached thereon by welding separate component etc. The manipulatingportion 662 is capable of receiving hand tool such as a box wrench bydetaching a detection plate 691 fixed by bolt on the upper side thereof,so that the nut 66 can be manually rotated. At the center of themanipulating portion 662, a grease nipple 697 is provided so that greasecan be fed to the screw 66A of the nut 66 etc.

[0106] The bolt 67 is attached to the connection bars 334E and 335Ethrough a joint component 671 on the lower side thereof, and a covercomponent 68 for covering the portion inserted into the case 31 of theadvancing-retracting portion 65 is provided between the joint component671 and the above mount base 805.

[0107] The cover component 68 is constructed by connecting a lower sidecylindrical portion 681 fixed to the joint component 671 and an upperbellows-shaped expandable portion 682 fixed to the mount base 805. Theupper end of the cylindrical portion 681 advancing and retractingtogether with the bolt 67 is in close contact with the outercircumference of the nut 66 through a ring-shaped sealing material 683.The length of the cylindrical portion 681 and the bolt 67 isapproximately equal, so that the sealing material 683 is always in closecontact with the outer circumference of the nut 66 within theadvanceable and retractable range (stroke) of the bolt 67, therebypreventing invasion of dust and water into the cylindrical portion 681.

[0108] The advancing-retracting portion 65 is inserted into thethrough-holes 81A, 805A and 631A of the movable case 80 and the drivemechanism 63, so that self weight thereof is received by thespring-receiving plate 631 through an oilless ring (nylon pad) 631B.Accordingly, the advancing-retracting portion 65 is not fixed at anypart in insertion direction thereof, so that the entireadvancing-retracting portion 65 rises in a manner for the fittingportion 661 to be away from the spring-receiving plate 631 at a time ofmalfunction when a big object collides with the rebound plate 33 withgreat force or an object is stuffed between the rebound plate 33 and theimpact plate 322.

[0109] At this time, since the movement locus of the connection bars334E and 334E at the tip end of the advancing-retracting portion 65draws an arc around the turning shaft 38 (FIG. 5), theadvancing-retracting portion 65 rises upward being slightly obliquelyinclined around a fulcrum of the contact portion with the through-hole805A of the mount base 805. When the advancing-retracting portion 65rises while being inclined, the cylindrical gear 633 and the exteriorcase 632 also incline, however, the inclination is absorbed by elasticdeformation of the rubber materials 636 and 637.

[0110] The advancing-retracting portion 65 after eliminating the risemoves back to downward on account of self-weight, weight of the reboundplate 33 and the first and the second arms 334 and 335, the impact etc.at the time being absorbed by the pair of coned springs 806.

[0111] The rise of the advancing-retracting portion 65 is also caused inadjusting the gaps C1 to C3, which will be described below.

[0112] According to the above-described gap adjuster 60, when the nut 66of the advancing-retracting portion 65 is rotated by the hydraulic motor64, the bolt 67 attached to the rebound plate 33 seamlessly advances andretracts without rotating in accordance with rotating amount androtating direction of the nut 66. The advancement and retraction of thebolt 67 moves (turns) the rebound plate 33 through the first and thesecond arms 334 and 335, thereby seamlessly adjusting the gaps C1 to C3between the rebound plate 33 and the impact plate 322.

[0113] [Arrangement of Gap Adjustment]

[0114] Next, a control method of the gap adjuster 60 in adjusting thegaps C1 to C3 will be described below.

[0115] The crusher 30 of the present embodiment has (1) full-auto mode,(2) automatic mode, and (3) manual mode for gap adjustment. Details ofthe respective modes will be described later, and the arrangementnecessary for controlling the gap adjuster 60 will be described below indetail with reference to FIGS. 6A and 7.

[0116] In FIGS. 6A and 7, the gear 634 constituting the drive mechanism63 of the gap adjuster 60 is provided with a disc-shaped detection disc692 having a plurality of notches on the circumference thereof. Arebound-plate-side rotation sensor (movement amount detecting means) 693that detects the notch of the rotating detection disc 692 and outputs adetection signal D1 to a controller 7 each time the notch is detected isprovided on the exterior case 632.

[0117] In the gap adjuster 60, the position of the detection plate 691provided on the upper end of the bolt 67 is detected by a rise sensor(rise sensing means) 694 attached through a bracket 807, which detectsthe rise of the advancing-retracting portion 65. Detection signal D2from the rise sensor 694 is also outputted to the controller 7.

[0118] A projection (dog) 323 located corresponding to the impact plate322 is provided on the rotation shaft of the rotor 32 and a rotor-siderotation sensor (rotation amount detecting means) 324 fixed on the case31 or bearing etc. by an appropriate fixing means is provided adjacentto the projection 323. The rotor-side rotation sensor 324 detects theprojection 323 rotated together with the rotor 32 to output a detectionsignal D3 each time the projection 323 is sensed.

[0119] The controller 7 has a CPU, a memory, program (software) storedin the memory for adjusting gap, a pulse counter, a timer, etc.

[0120] The controller 7 is connected with a changeover switch 501 forswitching the gap-adjusting mode into respective “full-auto”, “auto” and“manual” modes, an alarm 502 constructed by a buzzer, light etc. forindicating malfunction during gap adjustment, a first manual switch 503for vertically moving the first rebound plate 331 in the manual mode, asecond manual switch 504 for vertically moving the second and the thirdrebound plates 332 and 333 in the manual mode and an input panel 505attached with a liquid crystal panel where value can be inputted byoperating ten-keys.

[0121] Incidentally, upward movement of the rebound plate 33 is themovement away from the rotor 32 and downward movement is the movementtoward the rotor 32.

[0122] The controller 7 executes the program based on the detectionsignals D1 to D3 from the respective sensors 324, 693 and 694 and thesignal from the connected changeover switch 501, the first and thesecond manual switches 503 and 504 and the input panel 505, conductswitching operation by outputting a control signal D4 to the respectivecontrol valves 8A to 8C, controls the hydraulic motor 35 on the rotor 32side and the hydraulic motor 64 of the respective gap adjuster 60, andactuates the alarm 502 by outputting a malfunction signal D5 whenmalfunction is detected.

[0123] The controller 7 and the respective sensors 324, 693 and 694constitute a part of the gap adjuster 60 according to the presentinvention.

[0124] Though not illustrated in detail, the respective control valves8A to 8C of the main valve 8 are valves of four-port and three-position,which has a solenoid actuated by the control signal D4 from thecontroller 7 for switching position.

[0125] [Gap Adjustment: Full-Auto Mode]

[0126] Next, the control method of the gap adjuster 60 while adjustinggap in the full-auto mode will be described below with reference toFIGS. 7, 8, 9 and 10. Since the adjustment of the gap C1 between thefirst rebound body 331 and the impact plate 332 and the adjustment ofthe gap C3 (C2) between the third rebound plate 333 (second reboundplate 332) and the impact plates 332 are essentially equal, the first tothe third rebound plate 331 to 333 are collectively represented asrebound plate 33 and the gaps C1 to C3 are represented as gap C. Thesame also applies in the explanation of the automatic mode and manualmode described later.

[0127] In the full-auto mode, the impact plate 33 is automaticallyadjusted to the zero-point position where the rebound plate 33interferes with the rotation locus A of the tip end of the impact plate322 and is automatically moved away from the zero-point position by apredetermined gap. Accordingly, the full-auto mode accompanies thezero-point position determination.

[0128] The full-auto mode gap adjustment is conducted when totally newimpact plate 322 and rebound plate 33 are attached as in the case ofimmediately after the crusher 30 is shipped from factory, when it isnecessary to re-adjust the zero-point position of the rebound plate 33when one or both of the impact plate 322 and the rebound plate 33 areworn and exchanged, or when the zero-point position is shifted onaccount of abrasion of the impact plate 322 and the rebound plate 33thus increasing the size of the obtained object.

[0129] In order to conduct the gap adjustment by the full-auto mode, thechangeover switch 501 is switched to the “full-auto mode”. Then, theprogram corresponding to the full-auto mode is called from the memoryand executed in accordance with respective steps (ST) shown in FIGS. 9and 10.

[0130] ST1 in FIG. 9: Initially, the distance by which the rebound plate33 is moved away from the zero-point position (rotation locus A of thetip end of the impact plate 322) is inputted as a desired gap amount Ss.The gap amount Ss is inputted by operating ten-key in accordance withinstructions displayed on the input panel 505. The gap amount Ss isinputted by the unit of millimeter (mm). At this stage, as shown in FIG.8(A), the rotor 32 is stopped at a position and “pre-adjustment” gap Cis retained between the rotation locus A and the rebound plate 33.

[0131] ST2: Next, gap adjustment is started by pressing execute button(not shown) provided on the controller 7 etc. When the execute button isnot pressed, the inputted gap amount Ss is stored in a predeterminedmemory.

[0132] ST3: When the gap adjustment is started, the controller 7 clearsa pulse counter PCh for the rebound-plate-side rotation sensor 693 andsubsequently starts integration of the pulse number by the pulse counterPCh.

[0133] ST4: The controller 7 also clears the timer T in the controller 7and let the timer to count time.

[0134] ST5: Thereafter, the controller 7 outputs the control signal D4to the control valves 8B and 8C to switch to the communicating positionand drives the hydraulic motor 64 of the gap adjuster 60 in a directionfor the rebound plate 33 to be lowered.

[0135] ST6: Then, the controller 7 checks whether the pulse number ofthe pulse counter PCh is increased (increase toward minus side). Whenthe pulse number is increased, the controller judges that the reboundplate 33 is normally lowered toward the rotor 32.

[0136] ST7: On the other hand, when the pulse number is not increased,the hydraulic motor 64 is continuously driven until the time T reachesthree seconds. However, the interval setting of the timer T is notrestricted to three seconds, but may be changed in actualimplementation.

[0137] ST8: When the pulse number is not increased after three seconds,the controller 7 judges that the rebound plate 33 cannot be furtherlowered since the advancing-retracting portion 65 of the gap adjuster 60is extended to the maximum or the rebound plate 33 has already been incontact with the rotor 32, and switches the control valves 8B and 8C tostop the hydraulic motor 64 to suspend lowering the rebound plate 33.

[0138] ST9: Then, the controller 7 outputs the malfunction signal D5 tothe alarm 502 to notify an operator that the rebound plate 33 cannot belowered.

[0139] ST10: When the rebound plate 33 continues to be lowered normally,the rebound plate 33 touches, for instance, the rotor body 322 of therotor 32 as shown in FIG. 8(B). When the rebound plate 33 is furtherlowered after the contact, since the bolt 67 of the advancing-retractingportion 65 shown in FIG. 6A is not further advanced, the nut 66 movesupward.

[0140] Accordingly, in the ST10, whether the nut 66 has moved upward ornot is checked. When the detection plate 691 is out of detection rangeon account of upward movement and the rise sensor 694 becomes “OFF”, thecontroller 7 judges that the rebound plate 33 is in contact with therotor 32.

[0141] ST11: After it is judged that the rebound plate 33 touches therotor 32, the controller 7 switches the control valves 8B and 8C to ashut position to stop the hydraulic motor 64 to suspend lowering therebound plate 33.

[0142] ST12 in FIG. 10: Next, the controller 7 clears the pulse counterPCr for the rotor-side rotation sensor 324 and, subsequently, startsintegration by the pulse counter PCr.

[0143] ST13: Then, the controller 7 checks whether the pulse counter PCrexceeds “two”, i.e. two projections 323 (FIG. 7) have passed therotor-side rotation sensor 324 or not. In other words, the controller 7checks whether the rotation of the rotor 32 exceeds one fourth thereofand the impact plate 322 has passed the rebound plate 33 at least onceor not. Since the rotor 32 is not rotated, the process naturallyadvances to ST14.

[0144] Incidentally, the rotor 32 is rotated until two projections 323are detected because the impact plate 322 can go without being incontact with (passing) the rebound plate 33 only after one projection323 has passed. This is because the rotor-side rotation sensor 324 doesnot necessarily detect the projection 323 at the contact positionbetween the impact plate 322 and the rebound plate 33 (see positionrelationship between the rebound plate 33 and the rotor-side rotationsensor 324 in FIG. 7).

[0145] ST14: The controller 7 switches the control valves 8B and 8C to acommunicating position different from the previous position (in ST5), todrive the hydraulic motor 64 in a direction for raising the reboundplate 33 is raised.

[0146] ST15: When the lowering movement of the rebound plate is stoppedin ST11 (FIG. 9), since the nut 66 is slightly raised and the risesensor 694 is in “OFF” state, the nut 66 is moved downward before therebound plate 33 is moved away from the contact position with the rotor32 when the hydraulic motor 64 is driven in a direction for the reboundplate 33 to be raised in ST14, and the nut 66 is returned to initialposition before being raised. When the hydraulic motor 64 is furtherdriven, the bolt 67 is retracted to move the rebound plate 33 away fromthe contact position with the rotor 32.

[0147] Accordingly, in ST15, the controller 7 checks the output signalfrom the rise sensor 694 to monitor whether the nut 66 returns to theinitial position before being raised.

[0148] ST16: When the nut 66 is not lowered, the rotor 32 is stopped(since the rotor 32 is not rotated, the suspension of the rotor 32 ismaintained) and ST13 to ST16 are repeated until the nut 66 is lowered.

[0149] ST17: When the rise sensor 694 is in “ON” state when the nut 66is lowered, the controller 7 switches the control valve 8A to acommunicating position to rotate the rotor 32 while moving the reboundplate 33 upward. The rotation of the rotor 32 is continued, as describedin ST13, until the rotation from starting the rotation exceeds onefourth thereof, during which ST13 to ST15 and ST17 are repeated.

[0150] Incidentally, when the rotor 32 is rotated, one impact plate 322touches the rebound plate 33 until the rotation exceeds one fourththereof. After the impact plate 322 is in contact with the rebound plate33, since the rotation speed of the rotor 32 is faster than the speedfor raising the rebound plate 33, the impact plate 322 raises theadvancing-retracting portion 65 of the gap adjuster while rotating andset the rise sensor 694 in an “OFF” state.

[0151] At this time, the process advances from ST15 to ST16 and thecontroller 7 switches the control valve 8A into a shut position to stoprotation of the rotor 32 (see FIG. 8(C)). Then, the controller 7 againrepeats ST13 to ST16.

[0152] Accordingly, the routine from ST13 to ST16 and the routine fromST13 to ST15 and ST17 are alternately executed and the rotor 32 isdiscontinuously rotated while being in substantially close contact withthe rebound plate 33, so that the rebound plate 33 is discontinuouslyraised while being in substantially close contact with the rotor 32.

[0153] ST18, ST19: When it is judged that the rotation of the rotor 32exceeds one fourth in ST13, the controller 7 stops the movement of therebound plate 33 and the rotation of the rotor 32.

[0154] Accordingly, the tip end of the impact plate 322 passes and stopswhile tracing the circumference of the rebound plate 33. The reboundplate 33 is stopped substantially at the position where the reboundplate 33 starts interference with the rotation locus A of the tip end ofthe impact plate 322, the controller 7 determining the position of therebound plate 33 as the zero-point position (see FIG. 8(D)).

[0155] Incidentally, since the rotor 32 is necessarily rotated by onefourth, when the impact plate 322 touches the rebound plate 33immediately after rotating the rotor 32, the impact plate 322 rotatesmore after releasing the contact with the rebound plate 33 and therebound plate 33 moves farther upward to be greatly away from therotation locus A. However, since the movement speed of the rebound plate33 is very slow as compared to the rotation of the impact plate 322(rotor 32), the rebound plate 33 is not greatly moved away from therotation locus A and the accuracy of the zero-point position is scarcelyinfluenced.

[0156] ST20: After determining the zero-point position, the controller 7again clears the pulse counter PCh for the rebound-plate-side rotationsensor 693 and starts integration of the pulse number by the pulsecounter.

[0157] ST21: Then, the controller 7 drives the hydraulic motor 64 in adirection for the rebound plate 33 is raised to actually raise therebound plate 33.

[0158] ST22: The controller 7 calculates actual gap Sr (mm) relative tothe zero-point position caused by the movement of the rebound plate 33according to the following formula, where the pulse number of the pulsecounter PCh is M (pulse), and the moving amount of the rebound plate 33each time one pulse is counted is N (mm/pulse):

Sr=M*N

[0159] The moving amount N is determined considering decelerating ratiobetween the cylindrical gear 633 and the gear 634 of the gap adjuster60, screw pitch of the respective screws 66A and 67A and the arc shapeof the actual moving locus of the rebound plate 33.

[0160] ST23: Subsequently, the actual gap Sr increasing in accordancewith the increase (increase to plus side) in the pulse number of thepulse counter PCh is compared with the desired gap amount Ss set in ST1and the rebound plate 33 is moved upward until Sr becomes equal to Ss.

[0161] ST24: When Sr becomes equal to Ss, the controller 7 stops drivingthe hydraulic motor 64 to suspend the movement of the rebound plate 33.

[0162] According to the above-described ST20 to ST24, the distancebetween the impact plate 322 and the rebound plate 33 is adjusted to thedesired gap Ss (see FIG. 8(E)).

[0163] [Gap Adjustment: Automatic Mode]

[0164] In the automatic mode, the rebound plate 33 located at an initialposition is automatically moved upward or downward by an inputtedmovement amount to adjust the gap, which is conducted for changing thecurrent gap in order to obtain crushed objects of more desirable grainsize.

[0165] Specifically, there are varieties in the object to be crushed,e.g. concrete which is fragile and easily crushed into small size,asphalt which has viscosity and is difficult to be crushed in small sizeand hard natural stone which has no viscosity but is difficult to becrushed. In the impact crusher 30 using impact force for crushing theobject, in order to equalize the grain size of the final object, the gapamount between the impact plate 322 and the rebound plate 33 are oftenchanged (slightly widened) in accordance with the type of the object. Inother words, the gap is initially adjusted to standard gap by thefull-auto mode and the gap is minutely adjusted in accordance with thetype of the object by the automatic mode.

[0166] Further, when the impact plate 322 and the rebound plate 33 areworn, the gap may be adjusted by the full-auto mode accompanying thedetermination of the zero-point position or alternatively may beadjusted by the automatic mode instead of the full-auto mode to lowerthe rebound plate 33 by the abrasion, for instance.

[0167] In order to adjust the gap by the automatic mode, the current gapbetween the rotation locus A of the impact plate 322 and the reboundplate 33 are recognized in advance by manual measurement using gaugeetc., and the current gap is widened or reduced. However, the currentgap may be recognized not by the gauge but may be assumed based on thegrain size of the actually obtained object.

[0168] In adjusting the gap by the automatic mode, the changeover switch501 is switched to “automatic” mode. Then, the program corresponding tothe automatic mode is called from the memory and is executed inaccordance with respective steps shown in FIG. 11.

[0169] ST1 in FIG. 11: Initially, the distance for which the reboundplate 33 is moved from the current position is inputted as a desiredmovement amount Is from the input panel 505. At this time, in order tomove the rebound plate 33 downward, the movement amount Is is inputtedin minus setting and, in order to move the rebound plate 33 upward, themovement amount Is is inputted in plus setting.

[0170] ST2: Next, gap adjustment is started by pressing execute button(not shown) provided on the controller 7 etc.

[0171] ST3: When the gap adjustment is started, the controller 7 clearsa pulse counter PCh for the rebound-plate-side rotation sensor 693 andsubsequently starts integration of the pulse number by the pulse counterPCh.

[0172] ST4: The controller 7 calculates actual movement Ir of therebound plate 33 based on the pulse number M of the pulse counter PChand the moving amount N of the rebound plate per one pulse.

[0173] ST5: Subsequently, the controller 7 judges whether the inputteddesired movement amount Is inputted in ST1 is minus setting or plussetting.

[0174] ST6: When the movement amount Is is plus setting, the controller7 drives the hydraulic motor 64 to raise the rebound plate 33.

[0175] ST7: When the movement amount Is is minus setting, the controller7 drives the hydraulic motor 64 to lower the rebound plate 33.

[0176] ST8: Thereafter, the actual movement amount Ir increasing inaccordance with the increase in the pulse number (increase in plus-sideor minus-side) of the pulse counter PCh and the desired movement amountIs inputted in ST1 are compared and the rebound plate 33 is moved untilIr becomes equal to Is.

[0177] ST9: The controller 7 stops driving the hydraulic motor 64 tostop movement of the rebound plate 33 when Ir becomes equal to Is.

[0178] Accordingly, the rebound plate 33 is moved by the desiredmovement amount, thereby adjusting the gap between the impact plate 322and the rebound plate 33 to an appropriate amount.

[0179] Incidentally, a routine for checking normal increase in the pulsenumber and alarming malfunction when normal increase is not detected(corresponding to ST6 and ST9 in FIG. 9) may be added between ST6 andST7, ST8 as necessary.

[0180] Further, in the present embodiment, though the desired movementamount Is of the rebound plate 33 is set with reference to the currentposition of the rebound plate 33, if it is clear that there is nodeviation in the zero-point position determined in the full-auto mode,the movement amount Is may be set based on the zero-point position.

[0181] In this case, to what position relative to the zero-pointposition the rebound plate 33 is to be moved may be inputted as themovement amount Is.

[0182] Further, the pulse number (normally zero) of the pulse counterPCh at the zero-point position and the pulse number at the position ofthe current (before adjustment) rebound plate 33 may be stored and thenecessary movement amount from the current position of the rebound plate33 may be calculated based on the respective pulse number and theinputted desired movement amount Is. The rebound plate 33 is moved bythe necessary movement amount.

[0183] [Gap Adjustment: Manual mode]

[0184] In the manual mode, the rebound plate located at an initialposition is moved while the first and the second manual switches 503 and504 are pressed by an operator, which is different from theabove-described adjusting method conducted by operating the manipulatingportion 662 of the gap adjuster 60.

[0185] Such manual mode is effective in adjusting the gap withoutrequiring strict accuracy.

[0186] Incidentally, the movement amount while moving the rebound plate33 or the gap amount from the zero-point position may be calculatedbased on the changing pulse number of the pulse counter PCh and may besimultaneously displayed on the input panel 505 etc., the operatoroperating the first and the second manual switches 503 and 504 whilechecking the display.

Advantage of Embodiment

[0187] According to the above-described embodiment, following advantagescan be obtained.

[0188] (1) In the full-auto mode gap adjustment of the crusher 30, sincethe rise of the advancing-retracting portion 65 of the gap adjuster 60caused by the contact with the rebound plate 33 and the rotor 32 and therotation amount of the rotor 32 is detected and the zero-point positionof the rebound plate 33 is determined based on the detected result, itis not necessary to bring the rebound plate into contact with the rotorrotating in high-speed to generate vibration, thereby securelydetermining the zero-point position.

[0189] (2) The rebound plate 33 is not vibrated, so that the zero-pointdetermination can be conducted without being influenced by the abrasionof the rebound plate 33 and the impact plate 322. Accordingly, byadjusting the zero-point position and moving the rebound plate 33 fromthe zero-point position, the gaps C1 to C3 can be accurately adjusted.

[0190] (3) Since the initial contact between the rebound plate 33 andthe rotor 32 is detected by the rise of the advancing-retracting portion65 of the gap adjuster 60, the rebound plate 33 can be brought intosecure contact with the rotor 32 by initially moving the rebound plate33 down toward the rotor 32, thereby securely avoiding detection errorby avoiding non-contact state.

[0191] (4) Since whether the rebound plate 33 has reached the zero-pointposition or not is determined by detecting the rotation of the rotor 32,even when the rotor 32 enters into the rebound plate 33, that the rotor32 has entered into the rebound plate can be securely judged by therotation of the rotor 32, so that there can be no trouble in determiningthe zero-point position even when the advancing-retracting portion 65 isnot raised by the mutual contact, thereby further accurately determiningthe zero-point position.

[0192] (5) Further, in the automatic mode gap adjustment, since thecurrent gap of the rebound plate 33 is recognized in advance and therebound plate 33 is moved by the desired movement amount Is relative tothe current position, it is not necessary to collide the rebound plate33 with the impact plate 322 to vibrate, thereby accurately conductinggap adjustment.

[0193] (6) According to the automatic mode, since the movement amount Isis inputted based on the grain size of the actually obtained crushedobject, the gaps C1 to C3 can be minutely adjusted in accordance withthe type of the object even after the standard gap Ss is set by thefull-auto mode gap adjustment, so that crushed object of more accurategrain size can be easily obtained.

[0194] (7) By setting the movement amount Is of the automatic mode basedon the zero-point position, substantially the same gap adjustment as inthe full-auto mode can be conducted by the automatic mode within a shorttime, thereby efficiently conducting the gap adjustment.

[0195] (8) Since the advancing-retracting portion 65 of the gap adjuster60 has the screw-type mechanical moving mechanism 69 provided with thenut 66 and the bolt 67, the movement amount of the rebound plate 33 canbe minutely controlled by calculating the movement amount of the reboundplate 33 using the movement amount N based on screw pitch, and therebound plate 33 can be securely stopped at any position. Accordingly,the rebound plate 33 can be securely moved from the zero-point positionby the desired gap Ss or can be securely moved from the current positionof the rebound plate 33 by the movement amount Is, thereby furtheraccurately conducting the adjustment of the gaps C1 to C3.

[0196] Since the gaps C1 to C3 can be accurately adjusted, crushedobject of desired grain size can be securely obtained, thus improvingquality.

Second Embodiment

[0197]FIG. 12 shows a primary section of the gap adjuster 60 (61, 62)according to a second embodiment of the present invention. The samecomponent or the component of the same function as the componentdescribed in the gap adjuster 60 (61, 62) in the above-described firstembodiment will be applied with the same reference numeral to omit orsimplify the description therefor.

[0198] In the gap adjuster 60 of the present embodiment, the rise sensor694 is located beneath the exterior case 632 of the drive mechanism 63in the gap between the lower side of the exterior case 632 and the upperside of the movable case 80.

[0199] Specifically, the rise sensor 694 is supported by a support piece695 provided on the lower side of the exterior case 632 with the tip end(detection side) being inserted into an opening 631A drilled in thevertical portion of a cylinder 635, so that outer circumference 631C ofthe spring-receiving plate 631 accommodated in the cylinder 635 can bedetected.

[0200] On the other hand, though the spring-receiving plate 631 ismerely put on the coned disc spring 806 in the above-described firstembodiment, the spring-receiving plate 631 is biased upward by a helicalspring 696 provided around a through-hole 805A of the mount base 805 inthe present embodiment. Accordingly, when the advancing-retractingportion 65 of the gap adjuster 60 is raised, the spring-receiving plate631 follows the advancing-retracting portion 65 to be raised upward byvirtue of the spring force of the helical spring 696 (as shown in rightside in FIG. 12). The outer circumference 631C of the spring-receivingplate 631 goes out of the detection range of the rise sensor 694 asshown in double-dotted line in the left side of FIG. 12, and the rise ofthe advancing-retracting portion 65 is detected. Accordingly, nodetection plate 691 (see FIG. 6A) of the first embodiment is provided inthe present embodiment.

[0201] At this time, the through-hole 631A provided on thespring-receiving plate 631 is sufficiently greater than the outerdiameter of the nut 66 constituting the advancing-retracting portion 65,so that interference between the outer circumference of the nut 66 andthe through-hole 631A can be avoided even when the advancing-retractingportion 65 is obliquely raised in an inclined manner, thereby smoothlymoving the spring-receiving plate 631 up and down. Further, the outercircumference 631C side of the spring-receiving plate 631 is close tothe inner circumference of the cylinder 635 and the spring-receivingplate 631 is vertically moved while being guided by the innercircumference, thereby restraining shakiness during movement.

[0202] Further, in the present embodiment, the manipulating portion 662provided on the upper end of the advancing-retracting portion 65 is ofpolygonal (tetragonal, in the present embodiment) concave, into whichwrench etc. can be inserted for rotating operation. Further, a greasenipple 697 is provided on the upper end of the advancing-retractingportion 65 keeping away from the manipulating portion 662, so thatgrease can be fed into the nut 66 as in the first embodiment.

[0203] According to the present embodiment, following advantages can beobtained on account of specific arrangement thereof.

[0204] (9) Since the rise sensor 694 is located beneath the exteriorcase 632 of the drive mechanism 63, dust etc. is not fallen anddeposited on the rise sensor 694. Accordingly, the detection accuracy ofthe rise sensor 694 can be greatly improved and there is no need forimproving the detection accuracy using a greater sensor, therebyreducing cost and size thereof. Further, since the spring-receivingplate 631 to be detected by the rise sensor 694 is accommodated in thecylinder 635, deposit of dust on the spring-receiving plate 631 side canbe prevented, thereby maintaining superior detection accuracy for a longtime.

[0205] Further, since the rise sensor 694 is not projected upward unlikethe first embodiment, the damage on the rise sensor 694 on account ofscatterings from the outside can be avoided, thereby improvingdurability thereof.

[0206] (10) Since the outer circumference 631C of the spring-receivingplate 631 to be detected is located close to the fulcrum (through-hole805A of the mount base 805) when the advancing-retracting portion 65obliquely rises in an inclined manner, fluctuation of distance betweenthe rise sensor 694 and the spring-receiving plate 631 in accordancewith the inclination of the exterior case 632 can be virtually ignoredwhen the rise amount is small, thereby also improving the detectionaccuracy of the rise sensor 694.

[0207] (11) Since the outer circumference 631C of the spring-receivingplate 631 vertically moves while being guided by the inner circumferenceof the cylinder 635, shakiness movement during movement can be preventedand, even when the advancing-retracting portion 65 is greatly raised toincline the exterior case 632 and the rise sensor 694 greatly, thespring-receiving plate 631 can be moved in the inside of thesimultaneously-inclined cylinder 635 at a constant posture, therebysecurely detecting the outer circumference 631C with the rise sensor694.

[0208] (12) Since the spring-receiving plate 631 is a componentindependent from the advancing-retracting portion 65 and thethrough-hole 631A is set sufficiently large, it is unlikely for theouter circumference of the inclined nut 66 to be brought into contactwith the spring-receiving plate 631, so that the spring-receiving plate631 can be smoothly moved.

[0209] (13) Since the detection plate 691 as in the first embodiment isnot used and the manipulating portion 662 is provided on a sectionintegral with the advancing-retracting portion 65 in the presentembodiment, the structure can be simplified and the number of componentscan be reduced.

Modifications

[0210] Incidentally, the scope of the present invention is notrestricted to the above-described embodiments, but other arrangement ispossible as long as an object of the present invention can be attained,which includes following modifications.

[0211] Though the initial contact between the rebound plate 33 and therotor 32 is detected by the rise in the advancing-retracting portion 65and whether the rebound plate 33 has reached the zero-point position ornot is detected based on the rotation amount of the motor 32 in thecontrol method of the gap adjuster 60 in the first embodiment, whetherthe rebound plate 33 has reached the zero-point position or not may alsobe determined by detecting the rise of the advancing-retracting portion65. In other words, the position of the rebound plate 33 when the riseof the advancing-retracting portion 65 is not detected in spite of therotation of the rotor 32 may be determined as the zero-point position.Such control method and gap adjuster are well within the scope of anaspect of the present invention.

[0212] On the contrary, the initial contact between the rebound plate 33and the rotor 32 may also be detected by detecting the rotation amountof the rotor 32 as in determining whether the rebound plate 33 hasreached to the zero-point position or not. In other words, the contactbetween the rebound plate 33 and the rotor 32 may be determined when therotor 32 is not rotated by a predetermined amount even after the rotor32 is to be rotated relative to the rebound plate 33 at a predeterminedposition. Such control method and gap adjuster are also well within thescope of an aspect of the present invention.

[0213] Though the gap adjuster 60 in the above respective embodimentsare constructed by the screw-type mechanical moving mechanism 69 havingthe advancing-retracting portion 65 including the nut 66 and the bolt67, the advancing-retracting portion 65 may be a mesh-type mechanicalmoving mechanism having rack and pinion gear.

[0214] The connection between the rebound-plate side component (e.g.bolt component 67) and the rebound plate 33 according to the presentinvention may be a ball-joint type for driving the rebound-plate sidecomponent.

[0215] Alternatively, the advancing-retracting portion 65 may be ahydraulic cylinder, which can implement the control method according toan aspect of the present invention and can be applied to a gap adjusteraccording to an aspect of the present invention.

[0216] Though the hydraulic motors 35 and 64 are used as the rotor driveand the rebound plate drive according to the present invention in theabove-described respective embodiments, an electric motor may be usedinstead thereof.

[0217] Though the impact plate 322 has plate-shape in the firstembodiment, the impact plate according to the present invention is notrestricted to have plate-shape but may be designed in any mannerconsidering the shape of the rotor body and handlability in attachmentand exchange work.

[0218] Though the mobile crushing machine 1 according to the firstembodiment is self-running type having a crawler running section 10, themobile crushing machine 1 is not restricted to employ the crawler butmay have ordinary wheel, and the mobile crushing machine 1 may not beself-running type but may be a drawn-type.

[0219] The impact crusher of the present invention may not be mounted onthe mobile crushing machine 1 but may be fixed at a quarry, forinstance.

[0220] The specific arrangement, structure, type etc. of the controller7, the rotor-side rotation sensor 324, the input panel 505, therebound-plate rotation sensor 693, the rise sensor 694 etc. may bedetermined as long as an object of the present invention can beattained, which is not restricted to those described in the aboverespective embodiments.

What is claimed is:
 1. A control method of a gap adjuster (60, 61, 62)of an impact crusher (30), comprising the steps of: inputting a desiredgap amount (Ss) between a rotation locus (A) of a tip end of an impactportion (322) of a rotor (32) and a rebound plate (33, 331, 333); movingthe rebound plate (33, 331, 333) toward the rotor (32) using amechanical moving mechanism (69); determining a zero-point position ofthe rebound plate (33, 331, 333) based on interference between therebound plate (33, 331, 333) and the rotation locus (A) of the tip endof the impact portion (322); moving the rebound plate (33, 331, 333) tobe away from the zero-point position using the mechanical movingmechanism (69); and stopping the movement of the rebound plate (33, 331,333) in a direction away from the zero-point position when an actual gapamount (Sr) of the rebound plate (33, 331, 333) reaches the desired gapamount (Ss).
 2. A control method of a gap adjuster (60, 61, 62) of animpact crusher (30), comprising the steps of: moving a rebound plate(33, 331, 333) toward a rotor (32); detecting initial contact of therebound plate (33, 331, 333) with the rotor (32) based on a rise of arebound plate support (65) supporting the rebound plate (33, 331, 333);after detecting the rise of the rebound plate support (65), moving therebound plate (33, 331, 333) to be away from the rotor (32); rotatingthe rotor (32) to detect whether the rotor (32) again touches therebound plate (33, 331, 333) or not based on the rise of the reboundplate support (65); repeating the movement of the rebound plate (33,331, 333) to be away from the rotor (32) and the rotation of the rotor(32) until the rise of the rebound plate support (65) is not detected;and determining the position of the rebound plate (33, 331, 333) when itis judged that the rise of the rebound plate support (65) is notdetected as a zero-point position.
 3. A control method of a gap adjuster(60, 61, 62) of an impact crusher (30), comprising the steps of:rotating the rotor (32); detecting initial contact of the rebound plate(33, 331, 333) with the rotor (32) when the rotation amount of the rotor(32) becomes less than a predetermined rotation amount; after detectingthat the rotation amount of the rotor (32) does not exceed thepredetermined rotation amount, moving the rebound plate (33, 331, 333)to be away from the rotor (32); rotating the rotor (32) to detectwhether the rotor (32) again touches the rebound plate (33, 331, 333) ornot by judging that the rotation amount of the rotor (32) does notexceed the predetermined rotation amount; repeating the movement of therebound plate (33, 331, 333) to be away from the rotor (32) and therotation of the rotor (32) until the rotation of the rotor (32) exceedsthe predetermined rotation amount; and determining the position of therebound plate (33, 331, 333) when the rotation of the rotor (32) exceedsthe predetermined rotation amount as a zero-point position.
 4. A controlmethod of a gap adjuster (60, 61, 62) of an impact crusher (30),comprising the steps of: moving a rebound plate (33, 331, 333) towardthe rotor (32); detecting initial contact of the rebound plate (33, 331,333) with the rotor (32) based on a rise of a rebound plate support (65)supporting the rebound plate (33, 331, 333); after detecting the rise ofthe rebound plate support (65), moving the rebound plate (33, 331, 333)to be away from the rotor (32); rotating the rotor (32) to detectwhether the rotor (32) again touches the rebound plate (33, 331, 333) ornot by judging that the rotation amount of the rotor (32) does notexceed a predetermined rotation amount; repeating the movement of therebound plate (33, 331, 333) to be away from the rotor (32) and therotation of the rotor (32) until the rotation of the rotor (32) exceedsthe predetermined rotation amount; and determining the position of therebound plate (33, 331, 333) when the rotation of the rotor (32) exceedsthe predetermined rotation amount as a zero-point position.
 5. A controlmethod of a gap adjuster (60, 61, 62) of an impact crusher (30),comprising the steps of: recognizing a current gap between a rotationlocus (A) of a tip end of an impact portion (322) of a rotor (32) and arebound plate (33, 331, 333) in advance; inputting a desired movementamount (Is) of the rebound plate (33, 331, 333) relative to the rotationlocus (A) of the tip end of the impact portion (322); moving the reboundplate (33, 331, 333) toward or away from the rotor (32); and stoppingthe rebound plate (33, 331, 333) when an actual movement amount (Ir) ofthe rebound plate (33, 331, 333) reaches the desired movement amount(Is).
 6. The control method of a gap adjuster (60, 61, 62) of an impactcrusher (30) according to claim 5, wherein the rebound plate (33, 331,333) is moved using a mechanical moving mechanism (69).
 7. A gapadjuster (60, 61, 62) of an impact crusher (30), the impact crusher (30)having: a rotor (32) having an impact portion (322); a rebound plate(33, 331, 333) spaced apart from a rotation locus (A) of a tip end ofthe impact portion (322) by a gap (C, C1, C3); and a case (31) for therotor (32) and the rebound plate (33, 331, 333) to be attached, the gapadjuster comprising: a rebound-plate-side component (67) attached to therebound plate (33, 331, 333); a case-side component (66) screwed to ormeshed with the rebound-plate-side component (67) to be attached to thecase (31); a rebound plate drive (64) for rotating the case-sidecomponent (66) to move the rebound plate (33, 331, 333); a movementsensor (693) for detecting the movement amount of the rebound plate (33,331, 333); a set value inputting device (505) for setting and inputtinga desired movement amount (Is) or a desired gap amount (Ss) of therebound plate (33, 331, 333); and a controller (7) for controlling therebound plate drive (64) based on a detection signal from the movementsensor (693) and the desired movement amount (Is) or the gap amount (Ss)inputted by the set value inputting device (505).
 8. A gap adjuster (60,61, 62) of an impact crusher (30), the impact crusher (30) having: arotor (32) having an impact portion (322); a rotor drive (35) forrotating the rotor (32); and a rebound plate (33, 331, 333) spaced apartfrom a rotation locus (A) of a tip end of the impact portion (322) by agap (C, C1, C3), the gap adjuster comprising: a rebound plate support(65) for movably supporting the rebound plate (33, 331, 333); a reboundplate drive (64) for driving the rebound plate support (65) to move therebound plate (33, 331, 333); a movement sensor for detecting themovement amount of the rebound plate (33, 331, 333); a rise sensor (694)for detecting the rise of the rebound plate support (65) when therebound plate (33, 331, 333) touches the rotor (32); a set valueinputting device (505) for setting and inputting a desired gap amount(Ss) between the rebound plate (33, 331, 333) and the impact portion(322); and a controller (7) for controlling the rebound plate drive (64)and the rotor drive (35) based on a detection signal from the movementsensor (693) and the desired gap amount (Ss) inputted by the set valueinputting device (505).
 9. A gap adjuster (60, 61, 62) of an impactcrusher (30), the impact crusher (30) having: a rotor (32) having animpact portion (322); a rotor drive (35) for rotating the rotor (32);and a rebound plate (33, 331, 333) spaced apart from a rotation locus(A) of a tip end of the impact portion (322) by a gap (C, C1, C3), thegap adjuster comprising: a rebound plate support (65) for movablysupporting the rebound plate (33, 331, 333); a rebound plate drive (64)for driving the rebound plate support (65) to move the rebound plate(33, 331, 333); a movement sensor for detecting the movement amount ofthe rebound plate (33, 331, 333); a rotation sensor (324) for detectingthe rotation amount of the rotor (32); a set value inputting device(505) for setting and inputting a desired gap amount (Ss) between therebound plate (33, 331, 333) and the impact portion (322); and acontroller (7) for controlling the rebound plate drive (64) and therotor drive (35) based on a detection signal from the movement sensor(693) and the desired gap amount (Ss) inputted by the set valueinputting device (505).
 10. A gap adjuster (60, 61, 62) of an impactcrusher (30), the impact crusher (30) having: a rotor (32) having animpact portion (322); a rotor drive (35) for rotating the rotor (32);and a rebound plate (33, 331, 333) spaced apart from a rotation locus(A) of a tip end of the impact portion (322) by a gap (C, C1, C3), thegap adjuster comprising: a rebound plate support (65) for movablysupporting the rebound plate (33, 331, 333); a rebound plate drive (64)for driving the rebound plate support (65) to move the rebound plate(33, 331, 333); a movement sensor for detecting the movement amount ofthe rebound plate (33, 331, 333); a rise sensor (694) for detecting therise of the rebound plate support (65) when the rebound plate (33, 331,333) touches the rotor (32); a rotation sensor (324) for detecting therotation amount of the rotor (32); a set value inputting device (505)for setting and inputting a desired gap amount (Ss) between the reboundplate (33, 331, 333) and the impact portion (322); and a controller (7)for controlling the rebound plate drive (64) and the rotor drive (35)based on a detection signal from the rise sensor (694), a detectionsignal from the rotation sensor (324), and the desired gap amount (Ss)inputted by the set value inputting device (505).